256601136776761 has 32 divisors (see below), whose sum is σ = 308450004369408. Its totient is φ = 208703074789440.

The previous prime is 256601136776689. The next prime is 256601136776779. The reversal of 256601136776761 is 167677631106652.

It is a happy number.

256601136776761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256601136776761 - 2¹⁹ = 256601136252473 is a prime.

It is a super-2 number, since 2×256601136776761² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256601136776693 and 256601136776702.

It is not an unprimeable number, because it can be changed into a prime (256601136776791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 199965951 + ... + 201245083.

It is an arithmetic number, because the mean of its divisors is an integer number (9639062636544).

Almost surely, 2^{256601136776761} is an apocalyptic number.

It is an amenable number.

256601136776761 is a deficient number, since it is larger than the sum of its proper divisors (51848867592647).

256601136776761 is a wasteful number, since it uses less digits than its factorization.

256601136776761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289101.

The product of its (nonzero) digits is 80015040, while the sum is 64.

The spelling of 256601136776761 in words is "two hundred fifty-six trillion, six hundred one billion, one hundred thirty-six million, seven hundred seventy-six thousand, seven hundred sixty-one".